Indoor smoke exposure is responsible for two million deaths per year and has been studied globally, but the impacts of exposure have not yet been evaluated in Haiti, the Western hemisphere's poorest nation. This study measures the disproportionate impact of indoor smoke exposure on the women and children of Haiti. We studied 2296 clinic patients in four Haitian villages to determine the extent of carbon monoxide (CO) exposure, using carboxyhemoglobin saturation in the blood as a proxy for overall smoke exposure.